No abstract

Abstract:We consider the influence of higher-order terms in the leptodermous expansion used to extract the incompressibility K, of infinite nuclear matter from data on the breathing mode of finite nuclei. The terms we calculate are the curvature term Z&A -2'3, the surface-symmetry term Z& Z2A-"3, the quartic volume-symmetry term Z&Z+', and a Coulomb-exchange term. Working within the framework of the scaling model we derive expressions for their coefficients in terms of quantities that are defined for infinite and semi-infinite nuclear matter. We calculate these coefficients for four different Skyrme-type forces, using the extended Thomas-Fermi (ETF) approximation. With the same forces we also calculate the incompressibility K(A, I) for a number of finite nuclei, fit the results to the leptodetmous expansion, and thereby extract new results for the same coefficients. The comparison of the two calculations shows that the leptodermous expansion is converging rapidly. Of the new terms, the term K,Z4 is quite negligible, the curvature term should be included, and we discuss to what extent the other higher-order terms are significant.

K, -(300+25)MeV and an appreciable surface coefficient K,-(-750 *SO) MeV. We discuss the implication of this result for the incompressibility K,, of infinite nuclear matter.

Ahstrati We present a careful analysis of desaturation effects in densities and energies of nuclei using realistic Skyrme interactions in the extended Thomas-Fermi approach. Variational calculations confirm the slab model prescription introduced earlier for the extraction of desaturation terms for spherical systems. Desaturation is found to be appreciable in densities for A < 40 and in energies for A%4.

a t f i r s t handicapped by t h e f a c t t h a t t h e ETF f u n c t i o n a l s do n o t apply, i n general, t o s i t u a t i o n s where t h e d e n s i t y i s t i m e dependent, except f o r t h e case o f slow a d i ab a t i c motion.Although some formal progress has been achieved i n the f o u n d a t i o n o f time-dependent d e n s i t y f u n c t i o n a l t h e o r y / 9 / , ready-to-use f u n c t i o n a l s a r e n o t y e t a t hand.I n t h e study o f g i a n t resonances (GR) i t has been r e a l i z e d / l o / t h a t dynamical def o r m a t i o n s o f t h e Fermi sphere i n momentum space, which a r e missed when u s i n g t h e s t a t i c ETF f u n c t i o n a l s /11/, g i v e i m p o r t a n t c o n t r i b u t i o n s t o t h e r e s t o r i n g f o r c e s of some modes (e.g. a l l i s o s c a l a r e l e c t r i c m u l t i p o l e modes w i t h L 3 2 ) . These e f f e c t s , which i n an i n f i n i t e system l e a d t o Landau zero-sound e x c i t a t i o n s , have been i n c o rp o r a t e d t o v a r i o u s degrees of s o p h i s t i c a t i o n i n t h e s o -c a l l e d f l u i d -d y n a m i c a l approach and i t s v a r i a t i o n s /10,12-17/, l e a d i n g t o good agreement w i t h t h e r e s u l t s of RPA c a l c u l a t i o n s and -t o t h e e x t e n t t h a t t h i s i s t h e case f o r t h e RPA r e s u l t s -w i t h experiment. I n many o f these c a l c u l a t i o n s , however, v e r y schematic energy dens i t y f u n c t i o n a l s i g n o r i n g Coulomb and s p i n -o r b i t forces were used; t h e h i g h e r -o r d e r g r a d i e n t c o r r e c t i o n s t o t h e k i n e t i c energy, known t o be i m p o r t a n t t o reproduce c o rr e c t l y s t a t i c n u c l e a r s u r f a c e and d e f o r m a t i o n p r o p e r t i e s / I / , were o m i t t e d , too. Article published online by EDP Sciences and available at http://dx